<p>This work characterizes the blowup behavior of regularized solutions to the Jang equation within black hole regions, extending the exterior analysis of Schoen and Yau beyond apparent horizons. By applying geometric dilation and translation to blowup sequences, we demonstrate that the limits of properly translated solutions are constant null expansion surfaces (CES); specifically, the limit “cap" of the blowup sequence is shown to satisfy the constant null expansion equation. We further characterize the limits of rescaled solutions and establish a Structure Theorem for the interior of black hole regions arising from the Schoen–Yau regularization procedure. As a geometric application, we derive lower bounds for the area of apparent horizons and the ADM energy in terms of a quasi-local quantity of the second fundamental form of the initial data. Finally, we investigate the “slow-blowup" regime where rescaled solutions converge to zero, establishing both global and localized rigidity properties for the trivial blowdown limit and identifying topological constraints on the black hole regions where such limits occur.</p>